Electric heater



April 6 1926.

M, H. SHOENBERG ELECTRIC HEATER 1919 2 Sheets-Sheet 1 Filed Feb. 15,

Dbl/3622602":

17 11160121 J1. J/w/enb/er A ril a, 1926.

, 1,580,090 M. H. SHOENBERG ELECTRIC HEATER Filed Feb. 15, 1919 2 Sheets-Sheezt 2 wzizton (12157306225829;

Patented Apr. 6, 1926.

UNITED STATES.

1,580,090 PATENT OFFICE.

MILTON H. SHOENBERG, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO MAJESTIC ELECTRIC APPLIANCE COMPANY, INC., 013 SAN FRAN- CISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA.

ELECTRIC HEATER.

Application filed February 15, 1919. Serial No. 277,322.

T 0 all whom it may concern Be it known that I, MILTON H. Snonnmcne, a citizen of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements n Electric Heaters, of which the following is a specification.

This invention relates to'clectric heaters of the reflector type wherein the greater portion of the heat waves generated by a re sistance heating unit are directed by a polished metal reflector. This type of heater is disclosed in Patent 1,255,814and has become widely known as the Majestic heater. v p

The main object of the present invention is to provide a heating unit which possesses an increased efficiency over prior devices and when used in combination with a parabolic reflector, permits a large' number of heat waves to. strike the reflector at angles favorable to reflection in substantially parallel lines, the resultant effect of which is a greater degree of sensible heat pro ected to a distance from the heater.

- In the following detailed description of my invention I shall refer to the accompanying drawings, in which Figures} and 2 are fragmentary diagrammatic longitudmalscctional views of an electric heater provided with heating units embodying my invention; Fig. 3 is a side elevation partly in section, of the same heater, showing one manner of supporting the reflector upona base or stand; Fig. 4 is a longitudinal sectional view of the heating unit shown in Figs. 1 and 2; and Figs. 5 to 8 show various modifications of the heating unit.

I prefer to employ a reflector of-the type shown in the patent previously mentioned, .in which a polished metal reflector 2 of parabolic contour is secured in spaced relation to an 'out'er mctal shell, 3, which is suitably mounted upon a base or stand 4, the latter being preferably provided with a swivelled joint 5 to permit angular adjustment of the reflector. The shell 3-may be provided with a cooling flange 7 to which the cage of guard wires 8 is secured. I

The heating unit com rises a hollow core 10 having thin'walls o porcelain or other suitable refractory material which constitutes the support for the resistance wire12,

to the bore of the neck portion.

being preferably provided with grooves to retain the turns of wire in proper spaced relation. The bare resistance wire may be wound spirally from the rear end to the forward end of the core in alternate grooves and then in reversed direction between the turns of the first winding to the rear end. both ends of the wire 12 being threaded through apertures in the core wall and lead out through the bore of the core and connected in any suitable manner to the cord terminals 14:. The heating unit is arranged on the longitudinal axis of the reflector and is secured in position in any suitable manner. I have shown the hollow core provided with a collar or flange 16 adapted to shoulder against the reflector and having a rearwardly projecting neck 17, adapted to pass through central apertures in the reflector and outer shell and an insulating bushing 18 having a hollow plug portion 18 fitting in- The core neck may also be provided with lateral lugs '20 adapted to enter corresponding slots 21 in an inwardly pressed boss 23 in the shell, so that by first inserting the lugs and then partially turning the core it will be locked in the boss by a bayonet joint connection. Any other suitable fastening means may be employed.

'For the purpose of enabling a large proportion of the heat waves projected from the heated resistance wire 12 and from the hot walls of the core, to strike the reflector, I taper the rear portion of the core toward the reflector and I taper the forward end in the opposite direction so that the shape of the core comprises two truncated cones with their bases abutting. There is thus a definite line of demarkation between the direct radiation of the forward cone and the heat waves which are projected from the rearward cone to the reflecting surface.

The heat waves generated throughout all portions of each turn of the resistance wire radiate in all directions and by reason of the tapering form of the core the heat waves from each'turn that are projected laterally and rearwardly may strike the reflector and be reflected outwardly. Any heat waves which are on lines which if projected would pass through the focal point of the reflector will be reflected in lines parallel to the axis of the reflector.

The front tapering portion permits the heat waves thrown off at points forward of the zone of parallel reflection to be radiated in a forwardly extending direction, the forward taper thus contributing toward the eificiency of my heating unit in producing a maximum effect of sensible heat in the line of the axis.

The particular eifects produced may be varied by changing the shape of the core, making the taper of the forward end at a different angle and a different length from the rear end. I have illustrated this variation in the differentforms shown in Figs. 1 and 2. It is evident that the heating effects or distribution of heat may be altered to suit different conditions if desired 'by substituting one heating unit for another. -While I have shown the core having oppositely directed conical surfaces, which is my preferred form, I desire to cover in the appended claim such variations as may he made within the spirit of my invention.

I have illustrated a few modifications. Thus, in the form shown in Fig. 5, the outer end of the resistance wire issecured under the head of the bolt 20, which passes through the center of the core and constitutes the electrical conductor as well as the securing device. The rear end of the resistance wire passes through an aperture in the neck portion 17;

In Fig. 6, the neck of the core is provided with a threaded metal shell or plug 23, which may be secured by a nut on the bolt 20" which locks against the mica or other insulating washer 24. The threaded shell may be screwed into a socket carried by the reflector or outer casing, one end of the resistance wire being soldered to the shell which also serves as a connector.

In Fig.7, I have shown the core provided with a central longitudinal slot 25 and a central hole to receive the securing bolt. The neck or base of the core is provided with laterally projecting bars 26, which are perforated to receive screws 27. One end of the iesistance wire may be secured to the fastening bolt 26 while the other end may be threaded through the hole 29.

In the modification shown in Fig. 8, the core is provided with a central longitudinal bore, the rear portion 26 being adapted to receive a securing bolt. The neck 17 is provided with an annular flange 16, adapted to rest against the inner side of the reflector. The outer end of the core is provided with an annular flange 10 to form a protection" for the outer turns of the wire.

I claim: An electric heating unit for concave reflectors, comprising a hollow refractory core having oppositely tapering thin walls of.

double conical shape with abutting bases, the inner end of the core having an extension forming a support and provided with a fastening means, and a resistance wire wound about said core.

In testimony whereof I affix my signature.

MILTON H. SHOENBERG. 

